Research On Switching Noise Reduction In Low Power And High-voltage Power Supply

High frequency has become a development trend of switching mode power supply(SMPS),the semiconductor switching device operating frequency increases,making the issues of electromagnetic compatibility(EMC)more and more prominent.Electromagnetic interference(EMI)has caused a series of circuit stability problems,and has become a problem that must be faced and solved in the development of compact,planar and high power density power supplies.The power devices of high-voltage power supply(HVPS)work in a strong nonlinear state,with high dv/dt and di/dt.When not meet the EMC requirements,the switching noise will cause great interference to the surrounding electronic equipment.On the other hand,the switching loss increases significantly and the power efficiency is greatly reduced.Therefore,this dissertation focuses on the suppression of switching loss and switching noise.First of all,the analysis of domestic and foreign suppression technology research hot spots,compared that soft switching technology is the most effective way to solve the low power HVPS’s switching loss and switching noise.Secondly,the transient characteristics of power MOSFET and parasitic characteristics of high-frequency transformer are analyzed.The formation mechanism of the switching loss and the switching noise are explained.The stability of the feedback control circuit is analyzed based on the MATLAB simulation platform.The ANSYS Maxwell Magnetic simulation software helps analyzing some of the high-frequency transformer characteristics.Finally,a prototype of modular HVPS is designed.The test results show that the designed low power HVPS has successfully realized the design specifications,the switching loss and switching noise are effectively solved.